1. Field of the Invention
The preset invention relates to a remote controller, command transmission method, command receiving apparatus and personal computer apparatus, and, for example, is preferably applied to a remote controller that generates, in response to a pushing operation of a key, a transmission command and then transmits the transmission command.
2. Description of Related Art
In late years, it has become common practice to enjoy music and television programs on a personal computer, and a user uses an infrared remote controller and a Radio Frequency (RF) remote controller to handle music and television programs on the personal computer in the same way as television sets.
As shown in FIG. 1, the reference numeral 1 denotes a general infrared remote controller as a whole. An ON/OFF detection section 3 detects a pushing operation where a user pushes a remote controller key 2 disposed on a surface of a body (not shown).
While the remote controller key 2 is being pushed, the ON/OFF detection section 3 detects an ON state. The ON/OFF detection section 3 detects an OFF state, when the pushing operation of the remote controller key 2 stops. The ON/OFF detection section 3 then supplies these detection results to an ON code generation section 4.
When the detection result from the ON/OFF detection section 3 shows the ON state, the ON code generation section 4 generates at least three ON codes having a predetermined number of bits for each ON state. The ON code generation section 4 then supplies these ON codes to a modulation section 5.
The modulation section 5 modulates the three ON codes in a predetermined modulation manner. The modulation section 5 then supplies the modulated signals to a infrared transmission section 6 which then transmits the modulated signals to an infrared receiving section of a personal computer (not shown) as infrared signals.
As shown in FIG. 2, when the ON code generation section 4 detects the ON state in which one pushing operation of the remote controller key 2 is performed, the ON code generation section 4 transmits three continuous ON codes of the same pulse at intervals of approximately 50 msec by infrared radiation as a transmission command. Therefore, the ON code generation section 4 can certainly transmit the ON codes to the infrared receiving section of the personal computer, and this improves the reliability.
As shown in FIG. 3, while the ON code generation section 4 is detecting the ON state in which one pushing operation of the remote controller key 2 is performed for a long time, the ON code generation section 4 transmits continuous ON codes of the same pulse at intervals of approximately 50 msec by infrared radiation as a transmission command (The ON code generation section 4 transmits six continuous ON codes while the remote controller key 2 is being pushed, in this case).
Generally, if the remote controller key 2 is assigned to volume control, the continuous pushing operation of the remote controller key 2 is often performed. The longer the remote controller key 2 is pushed the more same size ON codes (nine, twelve, and more, for example) the ON code generation section 4 continuously transmits by infrared radiation as a transmission command.
As shown in FIG. 4, when the ON code generation section 4 detects that the remote controller key 2 is pushed twice within a very short period of time like double click, the ON code generation section 4 transmits six continuous ON codes, equivalent to two sets of three continuous ON codes of the same pulse at intervals of approximately 50 msec, by infrared radiation as transmission commands, although the key operation was performed twice. It is because the time between the first key operation and the second key operation is very short. As a result, the transmission commands are the same as the one having six ON codes as shown in FIG. 2, which are transmitted when the remote controller key is pushed for a long time.
This phenomenon is caused by performing the second key operation before the transmission of the transmission command (having three ON codes) corresponding to the first key operation is completed. That is to say, to improve the reliability, the more ON codes the ON code generation section 4 transmits for each key operation, the longer a user waits for the second key operation after the first key operation. The relationship between improvement of reliability and improvement of operationality is a trade-off.
As shown in FIG. 5, when a user pushes the remote controller key 2 such that the time between the first key operation and the second key operation is longer than double click (i.e., the user performs the second key operation after the transmission of the transmission command (having three ON codes) corresponding to the first key operation is completed), the ON code generation section 4 waits for some time to transmit the transmission command (having three ON codes) corresponding to the second key operation after completing the transmission of the transmission command (having three ON codes) corresponding to the first key operation.
The infrared receiving section of the personal computer, a receiver of the transmission command, accepts the received transmission command as valid, when the received transmission command includes two continuous ON codes of the same pulse within a period of 100 msec.
Accordingly, as shown in FIG. 5, even when the personal computer receives two transmission commands by the infrared receiving section, the personal computer mistakenly accepts them as one transmission command, since the reception interval between the last ON code in the transmission command corresponding to the first key operation and the first ON code in the transmission command corresponding to the second key operation is within a period of 100 msec.
Specifically, as shown in FIG. 6, the personal computer performs code determination process (routine RT1) to determine validity of the transmission command. The personal computer starts to perform the routine RT1 at start step, and then proceeds to next step SP1.
At step SP1, when the personal computer receives from the infrared remote controller 1 an infrared signal by the infrared receiving section, the personal computer proceeds to next step SP2. At step SP2, the personal computer demodulates and decodes the infrared signal to generate a reception command corresponding to the transmission command generated by the infrared remote controller 1. The personal computer then proceeds to next step SP3.
At step SP3, the personal computer controls a timer counter (not shown) to determine whether to detect two continuous ON codes within a period of 100 msec out of a plurality of ON codes making up the reception command. When negative result is obtained at step SP3, the personal computer proceeds to next step SP4.
At step SP4, since the interval between the ON codes, which make up the reception command, is more than 100 msec, the personal computer accepts the reception command as an OFF state, and then proceeds to next step SP7 without performing any process. The personal computer then ends the process.
By contrast, in a case in which the personal computer obtains affirmative result at step SP3 and also obtains two codes of the same pulse within a code-reception period of 100 msec, the personal computer then proceeds to next step SP5. In a case in which the personal computer obtains two codes of different pulses within the code-reception period of 100 msec, the personal computer then proceeds to next step SP6.
At step SP5, since the personal computer receives two continuous ON codes within the period of 100 msec out of the three ON codes making up the reception command, the personal computer accepts the reception command as valid, and then performs predetermined validity code process. The personal computer then proceeds to next step SP7 to end the process.
At step SP6, the personal computer accepts the reception command as invalid, because the first ON code and the second ON code are different in spite of receiving the two codes within the period of 100 msec. Accordingly, the personal computer performs code invalidity process, and then proceeds to next step SP7 to end the process.
In this manner, when the personal computer receives continuous ON codes of the same pulse within the period of 100 msec, the personal computer accepts the reception command as valid. Accordingly, when the interval between the last ON code in the transmission command corresponding to the first key operation and the first ON code in the transmission command corresponding to the second key operation is less or equal to 100 msec, the personal computer mistakenly recognizes the received transmission commands as one command including six ON codes generated by pushing the remote controller key 2 for a long time as shown in FIG. 3, in spite of the key operation performed twice at the infrared remote controller 1.
In order to solve the problem, there is an infrared remote controller device that allows a remote controller receiver to correctly recognize continuous key operation of the remote controller key 2 on the infrared remote controller (see Japanese Patent Laid-Open Publication No. 2003-3486762, for example).